Elucidating carrier transport mechanism in disordered amorphous oxide semiconductors to realize flexible fully solution processed oxide transistors

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K14291
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 21050:Electric and electronic materials-related
• Research Institution: Nara Institute of Science and Technology
• Principal Investigator: Bermundo Juan Paolo Soria 奈良先端科学技術大学院大学, 先端科学技術研究科, 助教 (60782521)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: 酸化物薄膜トランジスタ / 液体プロセス / プラズマプロセス / 酸素空孔 / レーザー / 薄膜欠陥 / 薄膜半導体 / 酸化物半導体

Outline of Final Research Achievements

We pioneered a sustainable method for producing high-performance, stable amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) through full solution processing. Unlike costly vacuum processes, we used sustainable techniques for all TFT layers, achieving remarkable mobility of up to 40 cm^2/Vs and enhanced stability. Achieve this milestone required a comprehensive understanding of how defect interactions affect conductivity and carrier transport in AOS. Employing plasma and photonic processes (solid-state laser and ultraviolet irradiation), we generated oxygen vacancy (Vo) defects in AOS, modulating conductivity and carrier concentration to create a multifunctional AOS serving as both channel and electrode. Addressing impurity issues inherent in solution AOS, we developed a method to intentionally precipitate impurities from the precursor, which greatly improved TFT performance. We also introduced a novel TFT structure resilient to defects which is promising for solution AOS.

Free Research Field

電子・電気材料工学

Academic Significance and Societal Importance of the Research Achievements

紫外線照射、固体レーザーアニール、プラズマプロセスなどのさまざまな活性化プロセスがAOSの特性に与える影響を慎重に研究しました。Arプラズマが効果的にVoを生成し、代替方法と比較して高性能かつ優れた安定性を持つ完全溶液プロセスTFTを作成することを実証しました。特にソリューションプロセスの文脈でのVoの科学的理解は、その安定性と性能の両方を改善するために重要です。さらに、完全溶液プロセスTFTの性能と安定性の向上は、高価な真空プロセスではなく持続可能なソリューションプロセスを使用して、すべてのTFT層を最小限の性能および安定性への影響で製造できることを示しており、社会的に重要です。